#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
#define MULTI 0
#define all(x) (x).begin(), (x).end()
#define dbg(x) cout << #x << " = " << x << "\n"
#define cin_vector(vec, n, T) vector<T> vec(n); for(ll i = 0; i < n; i++) cin >> vec[i];
template <typename ll> void print(vector<ll> &v){ for (auto &a : v) cout << a << " "; cout << "\n";}
template <class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
void solve() {
int n, base;
cin>>n>>base;
vector<int> a(n);
for(int i=0; i<n; i++){
cin>>a[i];
}
vector<int> poss_unch;
vector<int> b;
for(int i=1; i<=n; i++){
if(i*base>=a[i-1]){
b.push_back(i*base-a[i-1]);
}
}
// print(b);
vector<int> s;
for(auto p: b){
int pos = upper_bound(all(s),p) - s.begin();
if(pos==s.size()) s.push_back(p);
else s[pos]=p;
}
cout<<n-s.size()<<endl;
}
int32_t main() {
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); cout.precision(15); cout.setf(ios::fixed);
ll t=1; if(MULTI) cin>>t;
for (ll it = 1; it <= t; it++) {
// cout << "Case #" << it << ": ";
solve();
}
return 0;
}
